Cost-effective, large-scale techniques for concentrating and
purifying useful protein products from milk would benefit the dairy,
food, pharmaceutical and nutraceutical industries. A promising whey
protein separation technique, micellar extraction, could be an important
tool for obtaining these valuable food ingredients.

Reverse micelles are surfactant aggregates that have small polar
cores of solubilized water of macromolecular dimensions. Reverse
micelles can selectively purify recombinant proteins and their
intermediates from fermentation broths. Reverse micelles are able to
host proteins in an aqueous environment, effectively shielding them from
a nonmiscible apolar environment.

By using reverse micellar (RM) solvents to achieve protein-specific
isolations, researchers at the California Dairy Foods Research Center
have successfully developed strategies for separating beta-lactoglobulin
(p-LG), alphalactalbumin (a-LB) and immunoglobulin (IgG) from whey. What
we have here is a cost-effective separation process and an opportunity
to separate out whey proteins to create value-added products. In RM
separation, not only are protein molecules intact afterwards, but also
large scale-up of the necessary solutions is relatively uncomplicated.

The two primary components of whey, p-LG and a-LB, have desirable
functional properties when used as food ingredients, including the
ability to stabilize food emulsions as foams and to create protein-based
gels for confections, soups and sauces. These proteins are also valuable
for their nutritional quality. To benefit from the value of whey
proteins, manufacturers need an efficient and cost-effective approach
for separating proteins from whey, and for purifying the individual
elements of the whey protein mixture. Current commercial processes for
separating whey proteins are based on ultrafiltration and ion exchange
adsorption. The resulting protein mixtures have some valuable functional
properties in foods, but their usefulness could be enhanced by creating
products with better consistency and individual protein purity.

RM techniques have the potential to continuously extract specific
proteins from an aqueous mixture, achieving the simultaneous
concentration and purification of specific proteins. The RM solvent
contains small droplets of water, stabilized within an organic solvent
by a surfactant. Because protein molecules often move from an original
water phase into these small, encapsulated water droplets, RM extraction
is attractive for separating proteins from an aqueous solution.